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41.
Abstract Causality in changing natural systems can be seen to involve all four Aristotelian causal categories—material, efficient, formal and final. Final causality of materialistic origin can be found in the need to maintain energy flow continuity within dissipative systems. Each interacting dissipative system acts finalistically so as to attract needed energy. In so acting, it continually disturbs its neighborhood by generating potential energy flow disruptions as results of its activities. Final causality based, in this way, on the energy requirements of dissipative systems will generate formal causes as well. In contrast, the emergence of formal causes in mechanistic systems driven solely by efficient causes is extremely unlikely. We suggest viewing the subordination of phenotypic dissipative systems by genotypic counterparts as an historical example of the emergence of formal causes out of the material necessity of maintaining flow continuity. Functional separation between genotypic and phenotypic dissipative systems can occur if the energies to be dissipated are localized, as is the chemical binding energy of molecules with respect to biological functions at a higher scalar level. 相似文献
42.
The problem of convective diffusion from and reaction within the circulating flow inside a two-dimensional rectangular cavity is studied. The circulation is of the type induced by an external flow. Mass transfer occurs across the interface between the cavity and the external flow. A reactant may diffuse into the cavity from the external flow. The equations of steady motion and transient convective diffusion and chemical reaction are solved numerically. An enhancement factor is defined which quantifies the effectiveness of internal circulation in promoting diffusion and reaction. The dependence of this enhancement factor on geometry (cavity aspect ratio), Peclet number, and kinetic parameters is displayed. 相似文献
43.
P. STANLEY 《Fatigue & Fracture of Engineering Materials & Structures》2007,30(6):520-523
A recent publication includes a number of design calculations which incorporate iterative procedures. It is demonstrated that these are unnecessary and non‐iterative techniques are described for use in their place. 相似文献
44.
Prior research in this laboratory established apparent nonenzymatic toughening occurs in heat treated asparagus tissue. The present work attempted to identify the phenol compounds involved and to discern the mechanism(s) of this reaction. Toughness (Warner-Bratzler shear) of blanched (no detectable per-oxidase or polyphenol oxidase activity) spears stored at 22°C increased significantly over a 4 day period. Reverse phase-high pressure liquid chromatography (RP-HPLC) of methanolic tissue extracts indicated 7 major phenolic peaks. HPLC retention times and Fourier transform-infrared spectroscopy tentatively identified the extracted phenols as: (1) 4-hydroxybenzoic acid; (2) caffeic acid; (3) vanillic acid; (4) syringic acid; (5) p-coumaric acid; (6) syringaldehyde; and (7) ferulic acid. A significant decrease in the concentration (HPLC peak area) of 1, 2, 5, 6 and 7 occurred after 4 days storage. In vitro studies with homogenized (blanched and unblanched) asparagus tissue indicated a significant decrease in the concentration of added phenols. Unblanched tissue produced greater changes. The site of added phenol incorporation (a significant increase in fluorescence intensity) was determined to be the vascular bundle region. Metal ion chelation (EDTA), addition of iron (Fe2+ ) and reduction of metal ions using L-ascorbic acid affected added phenol utilization variably. Only the addition of a mixed antioxidant (BHA, PG, citric acid) served to significantly decrease utilization of the added phenols by blanched tissue blends, therefore implicating a free radical mediated phenol coupling mechanism. ESR spectroscopy detected the ascorbate radical anion in the blanched homogenate. 相似文献
45.
VALENTINA?ZHARKOVAEmail author STANLEY?IPSON ALI?BENKHALIL SERGEI?ZHARKOV 《Artificial Intelligence Review》2005,23(3):209-266
Despite several decades of research and development in the field of pattern recognition, the general problem of recognizing complex patterns with arbitrary orientations, locations, and scales remains unsolved and normally is applied using iterative manual evaluation of the detection results. This problem is becoming increasingly important with the growing number of massive archives of solar images produced by instruments located at ground-based observatories and aboard current satellites such as YOHKOH, SOHO and TRACE, with future satellites such as SOLAR B, SDO and STEREO in prospect. The size of expected archives requires a new automated approach to digital image processing and data extraction with robust and efficient pattern recognition techniques to be developed and implemented. This review evaluates techniques for the standardisation in shape and intensity of solar images and summarises the existing manual and semi-automated feature recognition techniques applied to a representative range of solar features, including sunspots, filaments, active regions, flares, coronal mass ejections and magnetic neutral lines. The review also surveys the most recent fully-automated detection techniques developed for the creation of Solar Feature Catalogues of sunspots, active regions and filaments for the European Grid of Solar Observations. The survey is aimed to help researchers and students to learn about the recognition techniques applied to astrophysical images with different levels of noise and distortions and to work effectively with the Solar Feature Catalogue. 相似文献
46.
EFFECT OF DEGREE OF COMPRESSION ON TEXTURE PROFILE PARAMETERS 总被引:3,自引:0,他引:3
Texture Profile Analysis (TPA) was performed on apple, carrot, frankfurter, cream cheese and pretzels with the Instron and the effect of the degree of compression on TPA parameters measured at a compression speed of 5 cm/min. Fracturability is almost independent of the degree of compression. Hardness, area 1, area 2, cohesiveness, gumminess, and chewiness usually increase with increasing compression but the rate of increase varies widely. Springiness increases for pretzel sticks and decreases for the four other commodities as compression increases. Adhesive force and adhesive area of cream cheese increase but stringiness decreases with increasing compression. Since the TPA parameters vary so widely with degree of compression, all TPA measurements should standardize the degree of compression and clearly state in reports what compression was used. 相似文献
47.
Free 14C-vitamin D3 decreased between 86.8–92.9% when incubated at 37°C with various fibers in the presence of 0.84% saline. The addition of bile as sodium taurocholate reversed the decrease in free vitamin D3 and was related directly to the concentration of the bile salt. Free 14C-vitamin E was also decreased in saline solutions with the fiber sources of hard red spring (HRS), soft white winter (SWW) wheat brans or alphacel cellulose (AC). In turn the decrease in free 14C-tocopherol was reversed by the addition of bile. Citrus pectin (CP) had no influence on the 14C-vitamin E. 相似文献
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22 FAMILIES, INCLUDING BOTH PARENTS AND THE 2 OLDER CHILDREN, WERE STUDIED AS THEY INTERACTED ON 4 TASKS. PATTERNS OF FREQUENCY OF "WHO TALKS TO WHOM" WERE FOUND TO BE HIGHLY STABLE FOR FAMILIES IN DIFFERENT SITUATIONS AND OVER TIME. THE LEADERSHIP PATTERNS OF THE 2 GROUPS OF FAMILIES WERE DIFFERENT: IN GENERAL, PARENTS IN NONCLINIC (NC) FAMILIES HAD MORE INFLUENCE THAN PARENTS IN CLINIC (C) FAMILIES, WHILE OLDER CHILDREN IN C FAMILIES HAD MORE INFLUENCE THAN THEIR COUNTERPARTS IN NC FAMILIES. C FAMILIES SHOWED LESS "RIGIDITY" OF CLIQUES THAN NC FAMILIES. IMPLICATIONS ARE RAISED FOR THE IMPORTANCE OF ROLE AND ORDINAL POSITION IN DETERMINING THE OPERATIONS OF MEMBERS IN THEIR FAMILY SYSTEMS. (15 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献